The helmet will make or break this build. Not the foam shaping, not the LED eyes. The hinge. I've seen probably thirty Iron Man helmets at cons where the faceplate doesn't flip cleanly because the builder mounted the pivot at the forehead instead of the temple line. You need that up-and-back arc, and you get it by epoxying two small hinges together at the temples with Chicago screws set in Apoxie Sculpt. I drilled through three helmet shells before I got the placement right on my fourth Mark III.

Forget the helmet for now though. Start with paint.

I'm serious. The number one thing that separates a $200 Halloween costume from a $500 cosplay-grade Iron Man suit is the paint job, and you cannot rush it. You need 3-5 coats of Flexbond on every single piece before primer touches foam. I do my sealing in batches across three days. Then gloss black primer (two thin coats, not one heavy coat), then your metallics. The community settled on Duplicolor Dark Cherry Metallic for the red and Duplicolor Sunburst Gold years ago and I've never found anything better. I picked up four cans of each at the O'Reilly Auto Parts on Sepulveda in Torrance last spring because they consistently stock Duplicolor when AutoZone doesn't.

Paint in a garage or outside. Never in your living space. And here's what nobody tells you: metallic paint looks completely different under fluorescent convention lighting versus your garage. Spray a test panel and bring it to a Home Depot. Stand under their overhead lights. The red will look darker and the gold will go flat. If you're not happy under fluorescents, add another mist coat of the metallic.

The 2K clear coat is non-negotiable. It's $28 for one can and it makes EVA foam look like actual metal. But 2K is a one-shot deal. Once you crack that can, you have about 48 hours before it hardens inside. Use it all, cure for two full days, don't touch anything.

On foam: I burned through a 6-pack of 10mm floor mats and three packs of 6mm sheets. Budget $55-60 just for foam. The whole build ran me about $420 because I already had a heat gun and contact cement. If you're buying tools from scratch, you're looking at the $500-550 range.

Scaling will frustrate you. Pepakura's exploded view dimensions don't match assembled dimensions, and every single body is different. Print your template pieces on cardstock first. Tape them to your body. My first chest plate was 4cm too narrow because I forgot that 10mm foam on both interior walls eats 20mm of clearance. Add 3cm to every circumference measurement. Do this before you cut a single piece of EVA.

The arc reactor is actually the fun part. A WS2812B LED ring with an Arduino Nano running a pulse animation looks incredible and draws less power than constant-on LEDs. Run a JST extension cable down to a battery pack in your pocket. Eight hours of runtime, no visible bulk.

Timeline is 8 weeks if you're disciplined about dry time. Most of that is waiting. Waiting for Flexbond to cure, waiting for primer, waiting for metallics, waiting for clear coat. The actual cutting and gluing is maybe 3 weeks of evenings. The rest is patience.

One more thing: make the cod piece removable. Side-release buckles. Trust me. A full suit takes 15-20 minutes to strip and you will need a bathroom at some point during a 6-hour con day. I learned this at Anime Expo 2023 and I don't want to talk about it further.